“The Obama administration halted construction on the Dakota Access oil pipeline Sunday, saying it would hold off on granting the final easement for the project while it conducts a thorough environmental review.

Both the developer and President-elect Donald Trump’s transition team have vowed to finish construction, while protesters say they could bring the conflict to court.

Here are five things to watch in the unfolding fight.

When Trump and his administration take office, approving Dakota Access probably won’t be as simple as signing a piece of paper.

The Army Corps of Engineers ordered an environmental impact statement for the project Sunday. Experts say that because of that, Trump’s administration will have to either complete the yearslong process or find a way to remove the requirement for testing the environmental impact. Doing the latter, however, would be a rare move that could subject the pipeline to a lawsuit.

Trump may look for a way to undo Obama’s decision so that the environmental review isn’t needed anymore.

Alternatively, Trump could wait for a decision from the federal District Court of the District of Columbia. It must rule on a motion from Energy Transfer Partners, Dakota Access’s developer, that the Army Corps must grant it a permit to build the pipeline.”